Field
The present disclosure relates generally to optic displays, and more particularly, to augmented vision eyeglasses having dynamically moving zone plates.
Background
Augmented vision eyeglasses, wherein synthesized images, such as text and symbols, are overlaid onto natural visual fields in an eyeglass package, are being touted as the next big thing for human computer interfaces. There is a fundamental optics problem of a big disparity in the focal parameters for the natural vision field, i.e., objects typically 12 inches or further away, and the overlay field, which is typically displayed on the eyeglass lens surface. Most solutions to date have bulky optics to fold the optical path length that is typically needed to solve the imaging problem. Such solutions display an overlay image as a two-dimensional (2D) collection of pixels and require the optics to form a virtual image at a far field distance (e.g., ≧12 inches), wherein the virtual image is subsequently reimaged by the eye lens onto the person's retina, through the eye lens. For example, in one solution, miniature liquid crystals are placed close on the eyeglass, with relay optics and a holographic coupler. These components operate together to overlay a synthetic image on the actual image being seen by the user. This solution involves a complex relay optical system and a display unit. Another problem associated with conventional augmented vision eyeglasses is the fact that people who wear prescription glasses require some adaptation of the optics to compensate for vision problems, such as near and far sightedness or astigmatism. Conventional solutions do not address this issue.